I've been happily using my Sharp LH79524 on a Logic PD card engine in my
design to control the display of a boiler exhaust gas analyser and I've
cracked most of the technical challenges leaving just the application to be
plugged away at.

However, some nice sales people have come in to talk about LCD panels but
also plugged a PXA270 board they were selling (for less than the Logic PD
board). I've had a quick look at the specs and peripherals on the xscale and
it is gusset-moisteningly funky. It's quick and has powerful LCD support and
also takes a camera input which might be useful. The dedicated MMC/SD
interface is also highly desirable (and could have saved me a good bit of
time). It also comes with a good whack more RAM and Flash than the Sharp
(128/128 as opposed to 32/16) which is always nice to have.

It comes with Windows CE on it, which puts me off a bit but should make
using the hardware easier but then I've already got the hardware running how
I want it on the Sharp.

I think if we'd looked harder at the Xscale 12 months ago we may have gone
that way but it wouldn't be impossible to change now - our compiler and
other tools are for ARM so they should work on the Sharp or the Intel and my
application code is system independent. The question is - is it worth
changing?

Tom Lucas wrote:

The parts are an order of magnitude apart in the performance ballpark.

Do you intend to do your own custom board at any time? The Sharp part
will be cheaper to prototype and assemble because it's available in
leaded flavors; all XScales are BGA. You'll also likely have fewer
EMI/EMC issues with the Sharp part.

If you do not need any XScale feature - which presumably you don't -
what is your reason for upgrading?

WinCE is not mandatory. Linux is extremely well-supported on XScale.

"larwe" <zwsdotcom@gmail.com> wrote in message
news:1145541655.534120.279970@z34g2000cwc.googlegr oups.com...
The certainly are. Perhaps I'm being greedy. I'm running on the ragged edge
of what the Sharp can do but it is coping and I don't plan to do anything
that will tip it over. However, with a more powerful part then I do some
really cool stuff such as live video and web servers. However, I may not get
time to so it become academic. It's all about whether the extra time would
be worth it. I guess that's for marketing to decide ;-)

The 79524 is BGA and we can't use a 79525 because it only has 16bit data
busses externally and a weaker LCD controller. The 79520 also doesn't have
as good an LCD controller and I've heard it's quite hard to get hold of at
the moment. We probably will make our own boards at some point in the future
and our PCB suppliers swear that they can do BGAs (I'll let them practice on
someone else's kit first) but buying in the card engines is making a lot of
sense for our relatively low volumes (<1000 units per year).

That is certainly another option. Mind you, I've survived until now without
an OS and have some good hardware drivers for the Sharp which could be
recycled with some effort. I wouldn't imagine UARTs, SPI and timer
peripherals to vary that wildly between the chips. Hopefully the LCD
controllers are both linear and my graphics library drivers would translate.

Or maybe I should stop lusting after faster hardware and get on coding for
what I've got!!!

On Thu, 20 Apr 2006 15:16:16 +0100, "Tom Lucas"
<news@REMOVEautoTOflameREPLY.clara.co.uk> wrote:

You are more likely to be able to buy the Sharp parts in 5 years time.
But I designed an SA1100 into a product ... and I'm still grouchy.

See:
http://www.intel.com/design/embedded...ors/302302.htm
which contains:
"Intel anticipates providing support for the Intel® PXA270 processor
for a minimum of five (5) years from launch, pending sufficient,
continued customer demand and other market conditions and factors. If
and when Intel decides to no longer provide support for these
products, we will follow our standard product discontinuance
notification guidelines of six months to place last time orders and an
additional six months to take delivery of the product."

Devices oriented at PDAs tend to have very short lifetimes, and it's
not just an Intel problem.

Stephen


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